@zzzzz9200
Looks like standard analysis
Whether or not it's human or engine would be unclear.
I'm thinking such knowledge is much older, predating engines.
But I could be wrong.
@paul-leggett saidPerfectly fine. This material has been in (real, paper) books for decades or even - certainly in the case of Philidor - centuries. Professional players have been expected to study and understand the theory, and indeed memorise key lines and positions. Even good amateurs ought to know the important bits.
@zzzzz9200
Absolutely not cheating.
Hell, even a complete patzer like me knows about the Lucena bridge, and Saavedra's trick, and which bishop you want for an edge pawn. And the latter at least has won me games. And I learned it all from human analysis in books. None of this is computer assistance, not even when it's put on the web.